Thermohydraulic and entropy characteristics of Al₂O₃‐water nanofluid in a ribbed interrupted microchannel heat exchanger

Abstract

In this study, an interrupted microchannel heat sink with rib turbulators was studied for its thermohydraulic effectiveness and entropy generation in a compact space. The rib edges are modified to enhance the overall functioning of the system by reducing the pressure drop. The working fluid used was Al2O3‐water nanofluid, and increasing the Reynolds number and nanoparticle concentration triggered a reduction in the heat sink's maximum temperature. These also offer a decrease in resistance to heat transfer, and there is an improvement in the evenness of the temperature of the interrupted microchannel heat sink, as regions with the likelihood of hot spot reduced drastically. At Re = 100, increasing the nanoparticle concentration from 0% to 4% enhanced the heat transfer coefficient by 38.41% for the interrupted microchannel heat sink‐base (IMCH‐B) configuration. Under similar conditions, the convective heat transfer coefficient for the interrupted microchannel heat sink‐fillet (IMCH‐F) increased by 43.69%. Furthermore, at 0.5% concentration, changing the Reynolds number from 100 to 700 augmented the heat transfer coefficient by 70.65%. Thus, the maximum temperature of the substrate's bottom surface was reduced by 53.83°C when the system was operated at Re = 700 and nanoparticle concentration of 4%. The IMCH‐C also showed relatively close results at all observed volume fractions. For the IMCH‐C, the maximum temperature of the bottom surface was reduced by 41.98°C at Re = 700 when compared with Re = 100% and 4% concentration. Although at high Reynolds numbers and concentrations, the pressure drops are higher, the performance enhancement criteria prove that the nanofluid is superior to water and the edge modifications show significant performance improvement. More importantly, the IMCH‐F heat sink showed the optimum performance based on the performance evaluation criteria at Re = 300 and φ=2% (ie, at this point, the heat transfer coefficient is maximum and the pressure drop is minimum). On the other hand, the optimal thermodynamic performance was observed at Re = 700 and φ=4%. The numerical results demonstrated a potential way to exploit nano‐suspensions for thermal applications, especially for high‐energy flux systems with compact space constraints.

Insight into three‐dimensional flow of three different dynamics of nanofluids subject to thermal radiation: The case of water–cobalt ferrite, water–manganese–zinc ferrite, and water–magnetite

“…Meanwhile, Areekara et al 30 accentuated the simultaneous effects of chemical reaction, stratification, induced magnetic field, and viscous dissipation for stagnation point flow of nanofluid utilizing magnetite and single‐walled carbon nanotubes (SWCNTs) nanoparticles. Other interesting work concerning nanofluids' flow with their heat transfer can be found here 31–38 . Furthermore, many researchers also deal with the significant impact of physical parameters like a magnetic field, suction/injection, heat generation, and chemical reaction as explained in detail by Singh et al, 39–41 Pandey and Upreti, 42 Upreti et al 43 and Joshi et al 44 …”

“…Other interesting work concerning nanofluids' flow with their heat transfer can be found here. [31][32][33][34][35][36][37][38] Furthermore, many researchers also deal with the significant impact of physical parameters like a magnetic field, suction/injection, heat generation, and chemical reaction as explained in detail by Singh et al, [39][40][41] Pandey and Upreti, 42 Upreti et al 43 and Joshi et al 44 Therefore, motivated by the above theoretical work and the significance of nanofluids in thermal enhancement, the present study numerically analyzes the thermal characteristic and fluid flow behavior of radiative MNFs over a permeable shrinking surface in a threedimensional system. Cobalt ferrite-water (CoFe 2 O 4 ), manganese-zinc ferrite-water (Mn-ZnFe 2 O 4 ), and magnetite-water (Fe 3 O 4 ) are chosen as examples of MNFs.…”

Optimization of heat transfer performance of CuO/H2O nanofluid in Bessel‐like converging pipe using a two‐phase mixture model

“…Besides the enhancement in HTP achieved by various passive methods discussed above, it is important to study their effect on EPR to minimize it. 17,18 Fadodun et al 19 examined laminar EPR of nanofluid in a linear converging pipe using FVM. The work examined the effect of convergent angle (α = 0-7.5°) and nanoparticle concentration φ ( = 0 − 3%) on the irreversibility distribution ratio (IDR).…”

Numerical study of the effects of geometric parameters and nanofluid properties on heat transfer and pressure drop in helical tubes

“…Adio et al [31] considered entropy generation and thermo-hydraulic effects in a microchannel heat sink with rib turbulators, where the Al 2 O 3 -water nanofluid used as a coolant. It was also found, to improve the system functioning, the rib edges can help to reduce the pressure drop.…”

“…These studies have been mainly focused on modifying the flow structure by changing heat transfer area, raising heat transfer surfaces, generating turbulent mixing. They have even considered making thinner boundary layers and enhance the heat transfer efficiency of the working fluid (2021) 3:722 | https://doi.org/10.1007/s42452-021-04701-6 by modifying thermophysical properties, such as discovering better thermal conductivities [29][30][31].…”